Poll: Reid moves ahead of Angle

Angle's support has fallen among Democrats, Republicans and independents

(CNN) -- Senate Majority Leader Harry Reid, D-Nevada, has taken a seven-point lead over Republican opponent Sharron Angle, according to a new poll published Friday in the Las Vegas Review-Journal.

The poll, conducted by Mason-Dixon, shows Reid ahead of Angle, 44 to 37 percent, with a 4 percent margin of error. The poll is the first Mason-Dixon survey showing Reid's lead exceeding the sampling error. Voters will decide the contest in November.

Ten percent of the poll's respondents were undecided, while 9 percent preferred someone other than the two major party candidates.

Reid's aggressive advertising campaign, according to the survey, has eroded Angle's support across the board. Angle's support has dropped 9 percent among men and 5 percent among women. While she still dominates among Republicans, her support has dropped by 11 percent with GOP voters. She's also fallen by 6 percent among independents, and 4 percent among Democrats.

The poll of 625 likely Nevada voters was conducted by phone from July 12-14.